1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (C) 2012,2013 - ARM Ltd
4 * Author: Marc Zyngier <marc.zyngier@arm.com>
6 * Derived from arch/arm/kvm/handle_exit.c:
7 * Copyright (C) 2012 - Virtual Open Systems and Columbia University
8 * Author: Christoffer Dall <c.dall@virtualopensystems.com>
11 #include <linux/kvm.h>
12 #include <linux/kvm_host.h>
14 #include <kvm/arm_psci.h>
17 #include <asm/exception.h>
18 #include <asm/kvm_asm.h>
19 #include <asm/kvm_coproc.h>
20 #include <asm/kvm_emulate.h>
21 #include <asm/kvm_mmu.h>
22 #include <asm/debug-monitors.h>
23 #include <asm/traps.h>
25 #define CREATE_TRACE_POINTS
28 typedef int (*exit_handle_fn)(struct kvm_vcpu *, struct kvm_run *);
30 static void kvm_handle_guest_serror(struct kvm_vcpu *vcpu, u32 esr)
32 if (!arm64_is_ras_serror(esr) || arm64_is_fatal_ras_serror(NULL, esr))
33 kvm_inject_vabt(vcpu);
36 static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run)
40 trace_kvm_hvc_arm64(*vcpu_pc(vcpu), vcpu_get_reg(vcpu, 0),
41 kvm_vcpu_hvc_get_imm(vcpu));
42 vcpu->stat.hvc_exit_stat++;
44 ret = kvm_hvc_call_handler(vcpu);
46 vcpu_set_reg(vcpu, 0, ~0UL);
53 static int handle_smc(struct kvm_vcpu *vcpu, struct kvm_run *run)
56 * "If an SMC instruction executed at Non-secure EL1 is
57 * trapped to EL2 because HCR_EL2.TSC is 1, the exception is a
58 * Trap exception, not a Secure Monitor Call exception [...]"
60 * We need to advance the PC after the trap, as it would
61 * otherwise return to the same address...
63 vcpu_set_reg(vcpu, 0, ~0UL);
64 kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
69 * Guest access to FP/ASIMD registers are routed to this handler only
70 * when the system doesn't support FP/ASIMD.
72 static int handle_no_fpsimd(struct kvm_vcpu *vcpu, struct kvm_run *run)
74 kvm_inject_undefined(vcpu);
79 * kvm_handle_wfx - handle a wait-for-interrupts or wait-for-event
80 * instruction executed by a guest
82 * @vcpu: the vcpu pointer
84 * WFE: Yield the CPU and come back to this vcpu when the scheduler
86 * WFI: Simply call kvm_vcpu_block(), which will halt execution of
87 * world-switches and schedule other host processes until there is an
88 * incoming IRQ or FIQ to the VM.
90 static int kvm_handle_wfx(struct kvm_vcpu *vcpu, struct kvm_run *run)
92 if (kvm_vcpu_get_hsr(vcpu) & ESR_ELx_WFx_ISS_WFE) {
93 trace_kvm_wfx_arm64(*vcpu_pc(vcpu), true);
94 vcpu->stat.wfe_exit_stat++;
95 kvm_vcpu_on_spin(vcpu, vcpu_mode_priv(vcpu));
97 trace_kvm_wfx_arm64(*vcpu_pc(vcpu), false);
98 vcpu->stat.wfi_exit_stat++;
100 kvm_clear_request(KVM_REQ_UNHALT, vcpu);
103 kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
109 * kvm_handle_guest_debug - handle a debug exception instruction
111 * @vcpu: the vcpu pointer
112 * @run: access to the kvm_run structure for results
114 * We route all debug exceptions through the same handler. If both the
115 * guest and host are using the same debug facilities it will be up to
116 * userspace to re-inject the correct exception for guest delivery.
118 * @return: 0 (while setting run->exit_reason), -1 for error
120 static int kvm_handle_guest_debug(struct kvm_vcpu *vcpu, struct kvm_run *run)
122 u32 hsr = kvm_vcpu_get_hsr(vcpu);
125 run->exit_reason = KVM_EXIT_DEBUG;
126 run->debug.arch.hsr = hsr;
128 switch (ESR_ELx_EC(hsr)) {
129 case ESR_ELx_EC_WATCHPT_LOW:
130 run->debug.arch.far = vcpu->arch.fault.far_el2;
132 case ESR_ELx_EC_SOFTSTP_LOW:
133 case ESR_ELx_EC_BREAKPT_LOW:
134 case ESR_ELx_EC_BKPT32:
135 case ESR_ELx_EC_BRK64:
138 kvm_err("%s: un-handled case hsr: %#08x\n",
139 __func__, (unsigned int) hsr);
147 static int kvm_handle_unknown_ec(struct kvm_vcpu *vcpu, struct kvm_run *run)
149 u32 hsr = kvm_vcpu_get_hsr(vcpu);
151 kvm_pr_unimpl("Unknown exception class: hsr: %#08x -- %s\n",
152 hsr, esr_get_class_string(hsr));
154 kvm_inject_undefined(vcpu);
158 static int handle_sve(struct kvm_vcpu *vcpu, struct kvm_run *run)
160 /* Until SVE is supported for guests: */
161 kvm_inject_undefined(vcpu);
166 * Handle the guest trying to use a ptrauth instruction, or trying to access a
169 void kvm_arm_vcpu_ptrauth_trap(struct kvm_vcpu *vcpu)
171 if (vcpu_has_ptrauth(vcpu))
172 vcpu_ptrauth_enable(vcpu);
174 kvm_inject_undefined(vcpu);
178 * Guest usage of a ptrauth instruction (which the guest EL1 did not turn into
181 static int kvm_handle_ptrauth(struct kvm_vcpu *vcpu, struct kvm_run *run)
183 kvm_arm_vcpu_ptrauth_trap(vcpu);
187 static exit_handle_fn arm_exit_handlers[] = {
188 [0 ... ESR_ELx_EC_MAX] = kvm_handle_unknown_ec,
189 [ESR_ELx_EC_WFx] = kvm_handle_wfx,
190 [ESR_ELx_EC_CP15_32] = kvm_handle_cp15_32,
191 [ESR_ELx_EC_CP15_64] = kvm_handle_cp15_64,
192 [ESR_ELx_EC_CP14_MR] = kvm_handle_cp14_32,
193 [ESR_ELx_EC_CP14_LS] = kvm_handle_cp14_load_store,
194 [ESR_ELx_EC_CP14_64] = kvm_handle_cp14_64,
195 [ESR_ELx_EC_HVC32] = handle_hvc,
196 [ESR_ELx_EC_SMC32] = handle_smc,
197 [ESR_ELx_EC_HVC64] = handle_hvc,
198 [ESR_ELx_EC_SMC64] = handle_smc,
199 [ESR_ELx_EC_SYS64] = kvm_handle_sys_reg,
200 [ESR_ELx_EC_SVE] = handle_sve,
201 [ESR_ELx_EC_IABT_LOW] = kvm_handle_guest_abort,
202 [ESR_ELx_EC_DABT_LOW] = kvm_handle_guest_abort,
203 [ESR_ELx_EC_SOFTSTP_LOW]= kvm_handle_guest_debug,
204 [ESR_ELx_EC_WATCHPT_LOW]= kvm_handle_guest_debug,
205 [ESR_ELx_EC_BREAKPT_LOW]= kvm_handle_guest_debug,
206 [ESR_ELx_EC_BKPT32] = kvm_handle_guest_debug,
207 [ESR_ELx_EC_BRK64] = kvm_handle_guest_debug,
208 [ESR_ELx_EC_FP_ASIMD] = handle_no_fpsimd,
209 [ESR_ELx_EC_PAC] = kvm_handle_ptrauth,
212 static exit_handle_fn kvm_get_exit_handler(struct kvm_vcpu *vcpu)
214 u32 hsr = kvm_vcpu_get_hsr(vcpu);
215 u8 hsr_ec = ESR_ELx_EC(hsr);
217 return arm_exit_handlers[hsr_ec];
221 * We may be single-stepping an emulated instruction. If the emulation
222 * has been completed in the kernel, we can return to userspace with a
223 * KVM_EXIT_DEBUG, otherwise userspace needs to complete its
226 static int handle_trap_exceptions(struct kvm_vcpu *vcpu, struct kvm_run *run)
231 * See ARM ARM B1.14.1: "Hyp traps on instructions
232 * that fail their condition code check"
234 if (!kvm_condition_valid(vcpu)) {
235 kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
238 exit_handle_fn exit_handler;
240 exit_handler = kvm_get_exit_handler(vcpu);
241 handled = exit_handler(vcpu, run);
248 * Return > 0 to return to guest, < 0 on error, 0 (and set exit_reason) on
249 * proper exit to userspace.
251 int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
254 if (ARM_SERROR_PENDING(exception_index)) {
255 u8 hsr_ec = ESR_ELx_EC(kvm_vcpu_get_hsr(vcpu));
258 * HVC/SMC already have an adjusted PC, which we need
259 * to correct in order to return to after having
260 * injected the SError.
262 if (hsr_ec == ESR_ELx_EC_HVC32 || hsr_ec == ESR_ELx_EC_HVC64 ||
263 hsr_ec == ESR_ELx_EC_SMC32 || hsr_ec == ESR_ELx_EC_SMC64) {
264 u32 adj = kvm_vcpu_trap_il_is32bit(vcpu) ? 4 : 2;
265 *vcpu_pc(vcpu) -= adj;
271 exception_index = ARM_EXCEPTION_CODE(exception_index);
273 switch (exception_index) {
274 case ARM_EXCEPTION_IRQ:
276 case ARM_EXCEPTION_EL1_SERROR:
278 case ARM_EXCEPTION_TRAP:
279 return handle_trap_exceptions(vcpu, run);
280 case ARM_EXCEPTION_HYP_GONE:
282 * EL2 has been reset to the hyp-stub. This happens when a guest
283 * is pre-empted by kvm_reboot()'s shutdown call.
285 run->exit_reason = KVM_EXIT_FAIL_ENTRY;
287 case ARM_EXCEPTION_IL:
289 * We attempted an illegal exception return. Guest state must
290 * have been corrupted somehow. Give up.
292 run->exit_reason = KVM_EXIT_FAIL_ENTRY;
295 kvm_pr_unimpl("Unsupported exception type: %d",
297 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
302 /* For exit types that need handling before we can be preempted */
303 void handle_exit_early(struct kvm_vcpu *vcpu, struct kvm_run *run,
306 if (ARM_SERROR_PENDING(exception_index)) {
307 if (this_cpu_has_cap(ARM64_HAS_RAS_EXTN)) {
308 u64 disr = kvm_vcpu_get_disr(vcpu);
310 kvm_handle_guest_serror(vcpu, disr_to_esr(disr));
312 kvm_inject_vabt(vcpu);
318 exception_index = ARM_EXCEPTION_CODE(exception_index);
320 if (exception_index == ARM_EXCEPTION_EL1_SERROR)
321 kvm_handle_guest_serror(vcpu, kvm_vcpu_get_hsr(vcpu));